Q. Find the coefficient of the x2 term in the binomial expansion of (4x+2)4.
Use Binomial Theorem: To find the coefficient of the x2 term in the binomial expansion of (4x+2)4, we will use the Binomial Theorem, which states that (a+b)n expands to a sum of terms in the form of C(n,k)⋅a(n−k)⋅bk, where C(n,k) is the binomial coefficient "n choose k". We are looking for the term where the power of x is 2, which means we need the term where k=2.
Calculate Binomial Coefficient: The binomial coefficient C(n,k) for the term where k=2 is C(4,2). This can be calculated as 2!(4−2)!4!=(2×1×2×1)(4×3×2×1)=6.
Find the Term: Now we need to find the actual term. The term with x2 will have a power of 2 for x and a power of 2 for the constant term. Therefore, the term is C(4,2)×(4x)2×22.
Calculate the Term: Calculating the term: 6×(4x)2×22=6×16x2×4=6×64x2=384x2.
Determine Coefficient: The coefficient of the x2 term is therefore 384.
More problems from Pascal's triangle and the Binomial Theorem